The present invention relates to an air filter system for a vehicle. It is particularly useful on trucks.
In the past, air filters for trucks have been mounted on the fender of the truck. More recently, they have been mounted beneath or in back of the cab by means of a special bracket fastened to the truck frame. It will be appreciated that the tenancy for increasing the load of trucks has resulted in a corresponding increase in engine power and size, thus resulting in the need to filter large volumes of air prior to combustion in the engine. As a consequence, air filters have become increasingly large, weighing as much as 50-100 pounds, when considering the mounting brackets, metal body, filter elements, and so on.
It will further be appreciated that the filter system undergoes substantial vibration during hauling. If an air filter system weighing 80--100 pounds is mounted on a truck fender, it is not long before the fender will begin to tear under the severe vibration encountered. If, on the other hand, the air filter is mounted directly to the truck frame, special brackets are required to secure the rather heavy filter system to the frame, and these mounting brackets normally require that holes be drilled through the brackets and through the frame of the truck in alignment with each other so that bolts may be passed through the aligned holes to secure the brackets to the frame. Even though this latter method of mounting is acceptable from an operational viewpoint, the costs of installation are substantial, and the weight of the brackets is considerable. For example, even though the empty weight of a truck may be thousands of pounds, each additional pound added to the empty weight of the truck reduces the load it may haul.
Still another problem with existing commercial air filter systems is that of maintenance. In some cases, it is difficult to get at the filter housing to remove the element. In other cases, it may be necessary to remove either the inlet air conduit or the outlet air conduit, or both, in order to replace the filter element. It is desirable, of course, to keep operating efficiency at a maximum by maintaining the filter elements as clean as possible.
In brief, the present invention provides a truck air filter system including a side wall which is an extension of the fuel tank already secured to the truck frame. In general, of course, it is desirable that the shape of the side wall of the air filter conform to the shape of the tank with which it is integral. For example, if the tank is cylindrical, then the side wall of the air filter housing is cylindrical.
Air is taken in through the side wall, passed over baffles for distributing it axially of the housing, and passed through the filter elements. After passing through the filter elements, the air is collected in a plenum which communicates with the outlet air conduit for delivering air to the engine.
The outlet air conduit passes through the front wall of the filter housing, and this front wall also includes a removable closure or door which may be removed without having to remove either the inlet air conduit or the outlet air conduit, so as to facilitate access to the filter elements for maintenance purposes.
Preferably, the side wall of the filter element is aluminum to further reduce the weight of the air filter system, although considerable weight saving is realized even if steel is used.
In summary, the present invention provides an air filter system for a truck which avoids fender-mounting as well as special mounting brackets and their attendant installation costs and weight. Weight is still further reduced by making the side wall of the filter housing of aluminum. It has been found, for example, that as much as 50 pounds may thus be eliminated in a filter system for a large truck. Still further, the present invention facilitates maintenance by permitting access to the filter elements without having to remove either the inlet or the outlet air conduit. Also, being mounted on a tank which is normally spaced behind the cab, the air filter itself is located in a more convenient, more accessible place.
Other features and advantages of the present invention will be apparent to persons skilled in the art from the following detailed description accompanied by the attached drawing wherein identical reference numerals will refer to like parts in the various views.